Why it never reaches the else part?

I'm new, so sorry for the bad code. It works, but it somehow never reaches the else part, regardless of what is the condition. I've tried multiple things, but nothing seems to work. Why?

let lock = true;

let screen = document.querySelector("#screen p");
let one = document.querySelector("#one");
let two = document.querySelector("#two");
let three = document.querySelector("#three");
let four = document.querySelector("#four");
let five = document.querySelector("#five");
let six = document.querySelector("#six");
let seven = document.querySelector("#seven");
let eight = document.querySelector("#eight");
let nine = document.querySelector("#nine");
let zero = document.querySelector("#zero");
let division = document.querySelector("#division");
let multiplication = document.querySelector("#multiplication");
let plus = document.querySelector("#plus");
let minus = document.querySelector("#minus");
let clear = document.querySelector("#clear");
let equal = document.querySelector("#equal");

let arr = [one, two, three, four, five, six, seven, eight, nine, zero];
let arr2 = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0"];
let fNum = "";

if (lock === true) {
  plus.addEventListener("click", function() {
    fNum += "+";
    screen.innerText += "+";
    lock = false;
  });
  minus.addEventListener("click", function() {
    fNum += "-";
    screen.innerText += "-";
    lock = false;
  });
  multiplication.addEventListener("click", function() {
    fNum += "*";
    screen.innerText += "*";
    lock = false;
  });
  division.addEventListener("click", function() {
    fNum += "/";
    screen.innerText += "/";
    lock = false;
  });

  clear.addEventListener("click", function() {
    screen.innerText = "";
    fNum = "";
  });

  for (let i in arr) {
    arr[i].addEventListener("click", function() {
      fNum += arr2[i];
      screen.innerText += arr2[i];
    });
  }
} else {
  let answer = "This part right here";
}